The proposed clinical research is concerned with the application and evaluation of biofeedback and relaxation methods in the regulation of blood pressure in patients with essential hypertension. Patients with mild (to moderate or severe) hypertension will be studied intensively and assigned to drug treatment, biofeedback, or a simple relaxation procedure. Extensive baseline data, including home and laboratory measurements, will be obtained. Following each treatment, comprehensive medical and physiological evaluations will be made. Patients will then be assigned to a second or third treatment in order to assess carry-over effects and to evaluate further the differential effectiveness of the different treatments. The broad objective of this research is to evaluate the usefulness of behavioral approaches to hypertension, as a possible adjunctive method of treatment, or as a possible alternative to drug treatment for patients whose hypertneison is not adequately controlled with medication, or for patients having undesired side effects of medication. A behavioral therapy may permit reduction of the required dosage of medication and of accompanying side effects. The proposed intensive case studies will provide systematic evidence concerning the value and potential of behavioral methods such as biofeedback and relaxation. If the answer is positive, at a later stage large-scale comparative studies of different behavioral strategies of treatment will be proposed, and applications of the procedures to other varieties of hypertensive disorder will be examined.